Saturday, September 27, 2014

When I found this butterfly, it was completely motionless. Closer inspection, however, showed that it was alive though torpid in the chilly morning. I let it crawl onto my finger, and my mammalian body heat must have given it a jump-start, because it fluttered out of sight.

Thursday, September 4, 2014

Though no living animal closely resembles Dendrogramma, at least three fossils bear a striking resemblance. Albumares, Anfesta, and Rugoconites appear to also to have possessed a disk laced with forking, radiating channels.

Those
enigmatic organisms have long captivated biologists with mysterious
forms that look like whirls, fronds, and shrubs, and it's still debated
whether they should be classified as animals. The life-forms are thought
to have vanished more than 540 million years ago at the end of the
Ediacaran period, just before a time of rapid animal evolution called
the Cambrian explosion.

It is possible that Dendrogramma
independently evolved a similar structure as a response to the same
conditions as the three extinct species, a common phenomenon called
convergent evolution.

"There is this most intriguing
similarity to certain Ediacaran forms," Conway Morris says. "[But] I
think the similarities are exactly that. They are intriguing rather than
compelling."

Still, there is a chance that Dendrogramma are Ediacaran descendants, potentially making these animals the first to survive to modern times in recognizable form.

"If this is true," says study co-author Reinhardt Kristensen,
an invertebrate zoologist at the University of Copenhagen, "then we
have discovered animals which we'd expect to be extinct around 500
million years ago."